Plant physiological response to insect injury and insecticide impact over soil arthropods

• Ano de defesa: 2002
• Autor(a) principal: Bastos, Cristina Schetino
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Interação Inseto-Planta; Ecotoxicologia; Trocas Gasosas; Aldicarb; Técnicas Multivariadas; Ciências Agrárias
• Link de acesso: http://www.locus.ufv.br/handle/123456789/10215

The growing need for environmental safety when dealing with pest control has led to the improvement of the approaches currently available to achieve this goal. In such context, methods that tend to envision pest problem in a more balanced way has gained importance. This study was carried out to evaluate soybean and potato response to the injury of phytophagous insects and the aldicarb impact over the inner coffee soil dwellers. To study plant response to insect injury two experiments were carried out: the first one was run on a potato field at Kearney County in south-central Nebraska, USA, and the second one was done on a soybean field at the University of Minnesota Rosemount Research and Outreach Center, Rosemount, MN, USA. On the potato field, it was carried out experiments in three different times: 07/12-13/2001, 08/1-2/2001, and 08/14-15/2001. The first and second one were represented by a 3 (varieties - Russet Norkotah, Atlantic and a Frito-Lays proprietary cultivar) x 2 (treatments – caged control and infested leaves) factorial and the third one was a 3 (varieties - Russet Norkotah, Atlantic and a Frito-Lays proprietary cultivar) x 3 (treatments – caged control, uncaged control and infested leaves) factorial, in both cases being the treatments arranged in randomized blocks with eight replicates. On the soybean field, the experiment envisioned three treatments which were low, intermediate and high aphid infestation levels which were arranged in randomized blocks with eight replicates. It was measured the potato gas exchange response and the soybean gas exchange, fluorescence, and stable carbon isotope ratio response to the redlegged grasshopper (Melanoplus femurrubrum Orthoptera: Acrididae) and soybean aphid (Aphis glycines Homoptera: Aphididae), respectively. With injury rates of about 10- 25% the potato gas exchange was not affected by the grasshopper. Soybean plants showed reductions of up to 50% on the gas exchange parameters of infested leaflets but did not alter the fluorescence parameters. To study the aldicarb impact over coffee soil arthropods, it was set up an experiment in a coffee plantation at the Federal University of Viçosa, Viçosa, MG, Brasil, with three treatments (control, one application of 10 g of Temik 150 (aldicarb)/plant and two applications of 10 g of Temik 150/plant) and four blocks, sampled one day before insecticide application and 13 different times after the insecticide application. There was significant effect of aldicarb application on the abundance of coffee soil arthropods based on different dispersion pattern of the control plots on the canonical axis when compared to plots treated once and twice with aldicarb. The plots which received one and two aldicarb applications did not differ significantly. The main species affected was mite morphspecies 4. KEY WORDS: Gas-exchange, insect-plant relationship, ecotoxicology, multivariate techniques, aldicarb.